1. Field of the Invention
The present device relates to a motor controlling, switch device suitable for controlling an electric motor which is used in a power window regulator, power sunroof or the like of an automobile.
2. Description of the Prior Art
In the prior art, for example, the power window of an automobile is equipped with a knob which is situated in a casing so that a restoring force is applied to the knob, thereby normally keeping it in its original position. The knob is moved from the original position to a first operating position by depressing it. The knob is turned from the first operating position to a second operating position by depressing it again. Thus, the knob is designed to operate in two steps. When the knob is positioned in the first or second operating position, a motor operating switch is turned on to complete the electric circuit for forward or reverse rotations of the motor to thereby open or close the window glass. There is also provided a holding switch which, when the knob is moved to the second operating position, is turned on to apply an electric current to the coil of an electromagnet adapted to attract and hold the knob at the second operation position. When the knob is turned to the first operating position, the window glass is continuously moved to open or close the window as long as the knob is kept at the first operating position. On the other hand, when the knob is set at the second operating position, the window glass is moved until the window is fully opened or closed even if the knob is released. When the window has been fully opened or closed, the driving motor is stopped and a locking current flows. There is known in the prior art a device which has a restoring member of a made material such as configuration storing or memory alloy to which locking current of 1 motor is applied. The configuration storing alloy is such that when it is heated it is restored to its original, unstretched shape. Thus when the configuration storing alloy is heated by the locking current, the restoring member is returned to its original shape, and the knob is returned to the original position against the attracting and holding force of an electromagnet by the restoring force of the restoring member.
The structure described above has to use the electromagnet to hold the knob in the second operating position and has the disadvantages of high manufacturing cost and power consumption.
In view of the forgoing disadvantages, it is an object of the present invention to provide a motor controlling switch device in which an operating member is returned to its original position, when the motor is stopped, and which need not use any electromagnet so that it is low in manufacturing cost and in power consumption.